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Drought killed off Tasmanian tiger: study

Drought was to blame for the extinction of Tasmanian tigers from the Australian mainland, a new study by the University of Adelaide has found.

Using DNA from fossil bones and museum specimens, the report says drought caused by the onset of El Nino weather patterns was the likely cause of the tiger's demise.

"The ancient DNA tells us that the mainland extinction was rapid, and not the result of intrinsic factors such as inbreeding or loss of genetic diversity," researcher Lauren White said.

Ms White said tigers lived in western regions of Australia right up to their extinction from the mainland around 3000 years ago.

The researcher said the reasons for the tiger's disappearance but continuing survival in Tasmania until the 1930s had remained a scientific mystery.

Previous theories include the introduction of dingoes and an increased Indigenous population.

But professor Jeremy Austin, said both groups went through a population crash at the same time and with no dingoes in Tasmania at the time and minimal population, weather was the most likely cause.

"Tasmania would have been somewhat shielded from the warmer, drier climate because of its higher rainfall but it appears that this population was also affected by the El Nino event before starting to recover," Mr Austin said.

The animal survived in Tasmania after European settlement but the local government offered a bounty for tigers claiming the animal was attacking sheep.

The last wild Tasmanian tiger was shot by a farmer in 1930 and the last in captivity died in 1936.

There have been numerous unconfirmed sighting ever since the animal was declared extinct.